Operating system: Ubuntu 18.04 64bit
Graphics card: GeForce GTX TITAN X (GM200), GeForce GTX 1080 Mobile (same behavior on both)
Broken: 2.80beta 17c15798c35f, 2.79b (same behavior with both)
Short description of error
When I start render from commanline, it is about eight times faster than the same render started by pressing F12 in Blender GUI.
Exact steps for others to reproduce the error
Try to open attached scene and run render by F12. Then try it from commanline by running
blender -b zzTmp-render-test2.blend -f 1